Shape file creation? An example!

[Doug Nebert]

Kieran:

Yesterday, ironically, I did just this kind of thing based on 
the simple script example in the shapelib directory as a script.
I wrote a perl script to receive the output from an earthquake 
checker program (finger quake at gldfs.cr.usgs.gov) -- a fixed column 
format file and fed it to the shapelib executables. It does use 
the "system" invocations but this should work with perl on either 
UNIX or NT since the invocations are the same in shapelib. Here 
is the little script. One thing to note is that you need to enter 
coordinates and attributes in the same order. (Something I could 
not make work was the ability to load numeric fields so I loaded 
all fields as text fields. -n option is either poorly documented 
or broken.):


#!/usr/bin/perl

# Assign location of shapelib executables
$qd = "/var/quakes";
# Assign location of mapserver data
$dd = "/var/mapserver/global/data";

system("rm -f $dd/quake.*");
system("$qd/shpcreate $dd/quakes point");
# This line creates 4 DBF text fields with lenghts 8, 8, 5, and 3
system("$qd/dbfcreate $dd/quakes.dbf -s Date 8, -s Time 8, -s Depth 5,
-s Mag 3");

while (<>) {
	if (/^99/) {
        $dat = substr($_,0,8);
        $tim = substr($_,9,8);
	$lat = substr($_,18,5);
	if ( substr($_,24,1) eq 'S' ) {
		$lat = $lat * -1 ;
	}
	$long = substr($_,26,6);
	if ( substr($_,32,1) eq 'W' ) {
		$long = $long * -1 ;
	}
	$depth = substr($_,34,5);
	$mag = substr($_,40,3);
	$place = substr($_,49,28);

#	print "$place $lat $long\n";
# This line pushes the point coordinates into the shapefile
	system("$qd/shpadd $dd/quakes $long $lat");
# This line pushes the four attributes into the DBF file
	system("$qd/dbfadd $dd/quakes.dbf $dat, $tim, $depth, $mag");
	}
}	

exit;



Kieran Ames wrote:
> 
> I'm shooting from the hip here...
> Does anyone know if there is anything like "txt2shp.exe" that could take
> a text file (or ODBC result) that contains points and looks like this:
> 
> NAME    LONG    LAT    ATTR_1    ATTR_2    ATTR_3        etc.....
> 
> and convert it to the appropriate shp, dbf, shx files?
> 
> TIA
> 
> Kieran

-- 
Douglas D. Nebert
Clearinghouse Coordinator 
FGDC Secretariat	Phone: +1 703 648 4151	Fax: +1 703 648-5755	
Pager Messaging: 	http://fgdclearhs.er.usgs.gov/dougmsg.html